What kind of allergy causes hives
The most common allergen is pollen, a powder released by trees, grasses and weeds that fertilize the seeds of neighboring plants. As plants rely on the wind to do the work for them, the pollination season sees billions of microscopic particles fill the air, and some of them finish up in people’s noses and mouths.
Spring bloomers include ash, birch, cedar, elm and maple trees, plus numerous species of grass. Weeds pollinate in the tardy summer and drop, with ragweed being the most volatile.
The pollen that sits on brightly colored flowers is rarely responsible for hay fever because it is heavier and falls to the ground rather than becoming airborne.
Bees and other insects carry flower pollen from one flower to the next without ever bothering human noses.
Mold allergies are diverse. Mold is a spore that grows on rotting logs, dead leaves and grasses. While dry-weather mold species exist, numerous types of mold thrive in moist, rainy conditions, and release their spores overnight. During both the spring and drop allergy seasons, pollen is released mainly in the morning hours and travels best on dry, warm and breezy days.
Hay fever treatments
Sarita Patil, an allergist with Massachusetts General Hospital’s Allergy Associates in Boston, talked to Live Science about strategies for outdoor lovers with seasonal allergies.
Patil suggested figuring out exactly what type of pollen you’re allergic to, and then avoiding planning outdoor activities during peak pollinating times in the months when those plants are in bloom. Numerous grasses, for example, typically pollinate in tardy spring and early summer and release most of their spores in the afternoon and early evening.
Her other strategies: Be capable to identify the pollen perpetrator by sight; monitor pollen counts before scheduling outdoor time; go exterior at a time of day when the plants that make you go achoo are not pollinating; and wear protective gear love sunglasses, among other tips.
[7 Strategies for Outdoor Lovers with Seasonal Allergies]
Allergy sufferers may also select to combat symptoms with medication designed to shut below or trick the immune sensitivity in the body. Whether over-the-counter or prescription, most allergy pills work by releasing chemicals into the body that bind naturally to histamine — the protein that reacts to the allergen and causes an immune response — negating the protein’s effect.
Other allergy remedies attack the symptoms at the source. Nasal sprays contain athletic ingredients that decongest by soothing irritated blood vessels in the nose, while eye drops both moisturize and reduce inflammation. Doctors may also prescribe allergy shots, Josephson said.
For kids, allergy medications are tricky.
A nationally representative poll of parents with kids between ages 6 and 12 found that 21% of parents said they had trouble figuring out the correct dose of allergy meds for their child; 15% of parents gave a kid an adult form of the allergy medicine, and 33% of these parents also gave their kid the adult dose of that medicine.
Doctors may also recommend allergy shots, a neti pot that can rinse the sinuses, or a Grossan Hydropulse — an irrigating system that cleans the nose of pollens, infection and environmental irritants, Josephson said.
Alternative and holistic options, along with acupuncture, may also assist people with hay fever, Josephson said.
People can also avoid pollen by keeping their windows closed in the spring, and by using air purifiers and air conditioners at home.
Probiotics may also be helpful in stopping those itchy eyes and runny noses. A review published in the journal International Forum of Allergy and Rhinology found that people who suffer from hay fever may benefit from using probiotics, or «good bacteria,» thought to promote a healthy gut. Although the jury is still out on whether probiotics are an effective treatment for seasonal allergies, the researchers noted that these gut bacteria could hold the body’s immune system from flaring up in response to allergens — something that could reduce allergy symptoms.
[5 Myths About Probiotics]
This article was updated on April 30, , by Live Science Contributor Rachel Ross.
Urticaria (hives) usually starts with a red, itchy patch of skin and develops into a raised welt with clearly defined borders. It is caused by an abnormal immune response. While this typically occurs as a result of an allergy to a food or medicine, there are non-allergic causes.
Symptoms may come and go quickly or be longer-lasting. Appearance may be enough for diagnosis, but chronic cases may require allergy testing, a physical challenge, or other tests. Antihistamines are typically used to treat urticaria, although H2 blockers, corticosteroids, antidepressants, and anti-asthma drugs may also be prescribed.
So, Youve Been Diagnosed with Hives!
by Richard S.
Do you really own the Hives?
Don’t despair. You’re not alone. Approximately 20% of the population will own hives (urticaria) at one time or another during their lifetime. First off, are you certain that they’re really hives? True hives are red, itchy, generally raised lesions that look very much love mosquito bites. They are often circular or oval but can be irregularly shaped.
Their size may vary from ¼ inch to several inches in diameter. They may blend together. Each spot lasts anywhere from hours and is surrounded by normal looking skin.
As they resolve the skin looks normal, not flaky or rough. While the hives are present one spot will be resolving while another nearby is developing. In about 40% of cases localized swelling (angioedema) of the lips, eyelids, hands, feet or tongue also occurs.
So, if these are really hives they must be from an allergy, right? Well, unfortunately it’s not that simple and modern science doesn’t own every of the answers. The history of how they first appeared and what’s happened to them since can provide significant clues as to what category of hives you own.
But first, what actually is a hive? Everyone’s skin is made up of numerous types of cells. One of these cells is called a mast cell. Everyone’s mast cells make and store histamine. They also routinely make leukotrienes and other substances that can cause localized inflammation. Mast cells don’t generally release much of these substances into the surrounding skin but if they do, these substances, especially histamine produce localized redness, itch and swelling we recognize as a hive or if it’s slightly deeper, angioedema.
So, if acute hives don’t seem to own an allergic cause what else could be going on? One of the more common presumed causes, especially in children is post-infectious hives.
During or within a week of viral, strep or other infections hives may happen through poorly understood mechanisms. This often leads to confusion when antibiotics own been given for the infection. Were the hives from the antibiotic or from the underlying illness? Post-infectious hives can recur for up to 6 weeks. At times, even without infection or any obvious trigger a few hours to a few days of hives happen. These are called acute idiopathic hives. We assume that the immune system is inappropriately activating the skin mast cells but we don’t know why.
We don’t ponder that stress is a common cause.
So, your hives own gone on for more than 6 weeks, so they drop into the chronic urticaria category. Now what? Once again you’re not alone. Approximately 3 million Americans of every ages own the same problem. There are some significant things that you should know. The first is that, unlike acute urticaria, less than 5% of the cases are due to some external cause. Also, unlike acute urticaria, the hives and /or swelling are rarely dangerous. In this form of hive problem various quirks and idiosyncrasies of the immune system, as they relate to mast cells, are the primary cause.
Our understanding of the problem is improving but there are numerous unanswered questions.
The best understood of these idiosyncrasies is called chronic autoimmune urticaria. Approximately 45% of every chronic hives are of this type. In this condition the immune system makes a detectable antibody (for which we own a test) that mistakenly thinks that parts of the mast cell surface are the enemy. This antibody attacks the skin mast cells which leads to the release of histamine, etc. It’s been known for a endless time that if our body makes one autoantibody type of error it’s easier for it to make other autoantibody mistakes. Therefore, it’s not terribly surprising that in chronic autoimmune urticaria approximately 20% of patients, especially women, will also own autoantibodies that target the thyroid gland.
This may lead to Hashimoto’s thyroiditis and periodically blood tests for thyroid function should be checked. Unfortunately, treating this thyroid condition probably does not benefit the hives.
The next most common type of chronic urticaria is chronic idiopathic urticaria. This condition is almost certainly due to the immune system’s interaction with mast cells but the details are unknown. Both chronic autoimmune and chronic idiopathic urticaria may worsen during febrile illnesses, with the use of aspirin family medicines, prior to the monthly menstrual period or with sustained pressure to or rubbing of the skin.
Individual hives that sting more than itch, leave bruises and final 3 or more days may indicate hives due to vasculitis (inflammation of the blood vessels).
Other forms of chronic hives own to do with the immune system’s reaction to physical triggers. Hives produced by stroking of the skin is called dermographism. Some people’s hives are triggered just by freezing, heat, skin pressure, vibration, exercise, sun or even water.
These conditions are fairly rare. Some exercise induced patients can either react just to exercise while others react only if their exercise follows the consumption of a food to which they are mildly allergic, most commonly wheat, celery and shellfish. These exercise reactions can produce anaphylaxis and may be dangerous. Another dangerous condition, this one involving angioedema and never hives, is called hereditary angioedema. In these patients swelling of the upper airway can be fatal.
Such patients also generally own pronounced abdominal pain from swelling of their intestines. Treatment is available.
So, now that you’ve put your hives into a category how are they treated? For acute hives and rare cases of chronic hives avoidance of triggers is the key. If the acute hives are already present antihistamines and if severe, a short course of oral steroid is used. For chronic hives daily preventative antihistamines are essential. Doses higher than those used for nasal allergy treatment are often needed. If maximum antihistamine dosing has been reached without control, addition of an H2 blocker (e.g. Tagamet) and/or a leukotriene blocker (e.g. Singulair) may be tried.
Maximizing the above therapy should minimize the need for oral steroid. Relying on recurrent courses of oral steroids (prednisone) especially without full antihistamine, H2 blocker and anti-leukotriene support is to be discouraged. In rare cases cyclosporin or other immunomodulatory medicines may be added. Once control has been achieved medicines should be continued for several weeks or longer past the final symptoms. Slow tapering can then be attempted.
So, why are my mast cells releasing histamine and other things when they shouldn’t?
The first question that needs to be asked is for how endless own you had hives? Hives that own been present intermittently or daily for less than 6 weeks are called acute hives, and if longer, chronic hives. Amongst the numerous possible causes of acute hives those due to allergic reactions get the most attention. In allergic patients the mast cells are coated with an allergy antibody, called IgE, that recognizes a extremely specific target (peanut, penicillin, yellow jacket, etc.). When that substance, such as peanut, becomes attached to that allergy antibody a chain reaction occurs that activates the mast cell which results in the release of histamine and other inflammatory substances.
A hive is born! For food allergy reactions, there are 3 useful rules to consider:
- First, the reaction begins quickly, within minutes of eating the food; on rare occasions up to an hour but almost never longer.
- Second, it goes away within a few hours or at the most within a day or two. Therefore, you never get hives for a week from one serving of peanut butter.
- Third, the reaction is reproducible, meaning that if hives were caused by eating 4 peanuts on a Monday, eating 4 peanuts the following week will almost always cause the same problem. Despite favorite belief, artificial food colorings and food additives almost NEVER cause hives.
Hives from antibiotics is a diverse situation.
The hive reaction can start anywhere from a few minutes after the first dose to 10 days after finishing the course. Antibiotic related hives can persist for up to approximately 2 weeks.
Allergic hives from stinging insects are generally obvious but occasionally they can be sneaky by occurring while you’re asleep or distracted. They start quickly after the sting and resolve in a few hours to a few days. In the U.S. spiders, flies and mosquitoes almost never cause hives although rare cases own been reported.
Almost any medicine or herbal product can potentially cause hives but one of the most common medicines implicated is the aspirin family (aspirin, ibuprofen, naproxen, etc.).
Isolated swelling without hives is a unique side effect of the ACE inhibitor blood pressure medicines. Soaps, detergents, fabric softeners almost never cause hives but if they do, the hives happen only where the skin is touched. Airborne allergy to pollen, dust, etc. almost never causes hives unless the person is in the midst of a massive hay fever attack. In an allergic person, direct skin contact with a potent allergic substance love animal saliva or latex can cause hives at the site. Every categories of allergic hives are potentially dangerous while chronic hives are generally not.
So, what’s my prognosis Doc?
As noted above:
- Acute hives resolve spontaneously.
- Less than 30% of idiopathic acute hives will go on to be chronic.
- If you own chronic hives that aren’t of the “physical” type at least 50% will resolve in less than a year and another 20% will resolve over the next several years.
The “physical” hives tend to be more endless lasting.
Research is ongoing in every of these areas. So hold your chin up, take your antihistamine, and get the necessary attention to the type of hives that you have.
Itchy eyes, a congested nose, sneezing, wheezing and hives: these are symptoms of an allergic reaction caused when plants release pollen into the air, generally in the spring or drop. Numerous people use hay fever as a colloquial term for these seasonal allergies and the inflammation of the nose and airways.
But hay fever is a misnomer, said Dr. Jordan Josephson, an ear, nose and throat doctor and sinus specialist at Lenox Hill Hospital in New York City.
«It is not an allergy to hay,» Josephson, author of the book «Sinus Relief Now» (Perigee Trade, ), told Live Science.
«Rather, it is an allergy to weeds that pollinate.»
Doctors and researchers prefer the phrase allergic rhinitis to describe the condition. More than 50 million people experience some type of allergy each year, according to the Asthma and Allergy Foundation of America. In , % of adults and % of children reported own allergic rhinitis symptoms, according to the Centers for Disease Control and Prevention (CDC). Worldwide, between 10 and 30% of people are affected by allergic rhinitis, Josephson said.
In , spring arrived early in some parts of the country and later in others, according to the National Phenology Network (NPN).
Spring brings blooming plants and, for some, lots of sneezing, itchy, watery eyes and runny noses. According to NPN data, spring reared its head about two weeks early in areas of California, Nevada and numerous of the Southern and Southeastern states. Much of California, for example, is preparing for a brutal allergy season due to the large quantity of winter rain. On the other hand, spring ranged from about one to two weeks tardy in the Northwest, the Midwest and the Mid-Atlantic U.S. [Watch a Massive ‘Pollen Cloud’ Explode from Late-Blooming Tree]
How do scientists know how much pollen is in the air?
They set a trap.
The trap — generally a glass plate or rod coated with adhesive — is analyzed every few hours, and the number of particles collected is then averaged to reflect the particles that would pass through the area in any hour period. That measurement is converted to pollen per cubic meter. Mold counts work much the same way.
A pollen count is an imprecise measurement, scientists confess, and an arduous one — at the analysis stage, pollen grains are counted one by one under a microscope. It is also highly time-consuming to discern between types of pollen, so they are generally bundled into one variable.
Given the imprecise nature of the measurement, entire daily pollen counts are often reported simply as low, moderate or high.
The American Academy of Allergy, Asthma & Immunology provides up-to-date pollen counts for U.S. states.
The symptoms of allergic rhinitis may at first feel love those of a freezing. But unlike a freezing that may incubate before causing discomfort, symptoms of allergies generally appear almost as soon as a person encounters an allergen, such as pollen or mold.
Symptoms include itchy eyes, ears, nose or throat, sneezing, irritability, nasal congestion and hoarseness.
People may also experience cough, postnasal drip, sinus pressure or headaches, decreased sense of smell, snoring, sleep apnea, fatigue and asthma, Josephson said. [Oral Allergy Syndrome: 6 Ways to Avoid an Itchy, Tingling Mouth]
Many of these symptoms are the immune system’s overreaction as it attempts to protect the vital and sensitive respiratory system from exterior invaders. The antibodies produced by the body hold the foreign invaders out, but also cause the symptoms characteristic of allergic responses.
People can develop hay fever at any age, but most people are diagnosed with the disorder in childhood or early adulthood, according to the Mayo Clinic.
Symptoms typically become less severe as people age.
Often, children may first experience food allergies and eczema, or itchy skin, before developing hay fever, Josephson said. «This then worsens over the years, and patients then develop allergies to indoor allergens love dust and animals, or seasonal rhinitis, love ragweed, grass pollen, molds and tree pollen.»
Hay fever can also lead to other medical conditions. People who are allergic to weeds are more likely to get other allergies and develop asthma as they age, Josephson said. But those who get immunotherapy, such as allergy shots that assist people’s bodies get used to allergens, are less likely to develop asthma, he said.
Tests & diagnosis
A physician will consider patient history and act out a thorough physical examination if a person reports having hay-fever-like symptoms.
If necessary, the physician will do an allergy test. According to the Mayo Clinic, people can get a skin-prick test, in which doctors prick the skin on a person’s arm or upper back with diverse substances to see if any cause an allergic reaction, such as a raised bump called a hive. [7 Strange Signs You’re Having an Allergic Reaction]
Blood tests for allergies are also available. This test rates the immune system’s response to a specific allergen by measuring the quantity of allergy-causing antibodies in the bloodstream, according to the Mayo Clinic.